73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Als87 on April 03, 2013, 11:18:36 pm
-
I have an '87 with a 350 that has a small oil leak. Ive been tryin to pinpoint the leak & I'm pretty sure its the back corner of the driver side valve cover.
It seems to "throw up" a little oil each time i start it but not leak much other than that. when i park it will slowly drip just a bit but the majority gets dumped when i fire it up. Does this sound consistent with a valve cover leak? Im pretty sure thats where its at but i figured Id use the forum & see what u guys thought.
Thanx in advance for any feedback/suggestions or advice.
God bless
'87 shortbed
350 w/ 350 turbo
1/2 ton
4x4
4" lift on 35's
-
My 85 use to do the same thing but it was the passenger side. I eventually got the clamps that go over the valve covers that bolt right on and got a rubber gasket and some gasket sealer and the problem stopped.
-
Do you have an oil pressure gauge? On my 79 the back drivers side corner is where the tubing is hooked up. Right past the end of the valve cover. The tubing to the gauge may have a small crack right at the fitting, especially if its the plastic type. This already happened to me. Replaced it with copper tubing. Your pressure sending unit is in the same place if no gauge. Check to see if its leaking around the threads. Just a couple of easy checks before pulling your valve cover.
-
thanx guys. Yea i do have a oil pressure guage hooked up that seems to be working fine but is probably worth a look while im under the hood saturday.
-
Sometimes they don't leak bad enough to affect the operation of the gauge but it will still leak enough to know you have a leak.
-
best thing to do is clean it all up. then start fresh dont drive it cause the wind coming from the underside will blow the oil all around
-
Do you have an oil pressure gauge? On my 79 the back drivers side corner is where the tubing is hooked up. Right past the end of the valve cover. The tubing to the gauge may have a small crack right at the fitting, especially if its the plastic type. This already happened to me. Replaced it with copper tubing. Your pressure sending unit is in the same place if no gauge. Check to see if its leaking around the threads. Just a couple of easy checks before pulling your valve cover.
Guess this is a common problem just got 79 and that is exactly where mine was leaking
-
Got em replaced after wrk last nite. The gaskets were definitely bad, I could see where it was leakn, & it's no wonder cuz they were cork gaskets ugh. Why not spend the few xtra dollars for decent rubber gaskets!?
With that being said, the corner still leaks just a very little bit but it's still a drip. I'm gonna pull it off again tmoro aftr church & double check the head surface & hopefully stop the drip.
The oil pressure line to the guage seems fine.
Thanx again guys
-
Well I determined its gotta b the backside of the intake. That's nex weekends project
-
use some rtv gasket maker and throw away the rubber gasket for the intake.
-
use some rtv gasket maker and throw away the rubber gasket for the intake.
^best thing ever to do 8)
-
i would even go as far as using it on one side or the other of the valve cover gasket just not both or you wont get it back off again
-
thats what i heard from a guy at work too. i had bought some gasket sealer but i need to get the good blue or orange gasket maker. is that the rtv stuff? this oil leak is drivin me nuts
-
rtv orange. each one is for diffrent things ie one for fuel one for high temp one for oil contact. (http://a248.e.akamai.net/origin-cdn.volusion.com/adets.qcfpr/v/vspfiles/photos/7087-2.jpg)
SENSOR SAFE
Formulated for Hi-Temp and Heavy Duty Use
Resists cracking, shrinking and migrating caused by thermal cycling
Coats pre-cut gaskets to increase reliability
Temperature Range = -75F to +600F continuous; -75F to +650F intermittent
Pressure-resistant - stays flexible
Gasket maker or dressing
Applications = Valve Covers, oil pans, intake manifold end seals, timing covers, water pumps, thermostat housings and other high temp. areas
they even make copper ones
http://www.permatex.com/products/product-categories
-
I can't find the orange at any of the auto parts stores round here. Can I use the black one for the intake?
-
Try to find Permatex Ultra Grey or Ultra Copper.
-
I'm assuming since your truck is an 87 model that you have centerbolt valve covers then ? If so, the gaskets are rubber and require absolutely no sealant. Install them dry and torque the four bolts. They won't leak.
On the intake manifold, replace gaskets and use a 1/4 inch bead of black silicone in place of the front and rear rubber seals that come in most gasket kits. Felrpo kits come with a small tube of silicone and instructions to do it this way.
That is the way GM trained me when I worked in a dealership. They had so many warranty claims on leaking manifolds that they released a service bulliten on the matter explicitly explaining to do it this way and never use the rubber end gaskets.
-
It is an '87 but it's not the original motor. Well at least the intake ain't cuz an '87 should b a throttle body but I have a 4barrel (q-jet)
The guy I bought it from had started to put some wrk into it but ran out of $ & lost his license so had to sell the truck to pay fines. So I got a super deal on the truck. Solid body, no rust but I could tell he ran out of money cuz there's a couple upgrades on the rebuilt motor but some other stuff was either done cheap or rushed so I'm tryin to find where he left off lol.
I did find the orange rtv sealer & hope I have a few hrs this wk to replace that.
I will replace the gasket but toss the rubber seals & put a nice bead around the intake.
-
i dont see why not but i cant say it will work never used it before on the manifold
-
I had the same issue until this weekend. Spent the majority of Saturday pulling off the intake and replacing. The guy that just installed my engine put the smallest amount of clear silicon and it was leaking at the corner where the intake,block and head meet. I put on a good bead of high temp RTV and new gaskets. No more oil leak. Pain in the butt for my old out of shape self, but saved $$$. Hope you got yours fixed.
-
clear silicone? didnt think it was made to handle contact with oil and heat lol
-
appearantly not. Hence the oil leak! Still debating on kicking that guys :(